建造者模式java程序demo

好的，下面是建造者模式的Java程序示例：

// Product类，表示需要被构建的复杂对象
class Product {
    private String partA;
    private String partB;
    private String partC;

    public void setPartA(String partA) {
        this.partA = partA;
    }

    public void setPartB(String partB) {
        this.partB = partB;
    }

    public void setPartC(String partC) {
        this.partC = partC;
    }

    public String getPartA() {
        return partA;
    }

    public String getPartB() {
        return partB;
    }

    public String getPartC() {
        return partC;
    }
}

// Builder类，定义了如何构建Product对象的接口
abstract class Builder {
    protected Product product = new Product();

    public abstract void buildPartA();

    public abstract void buildPartB();

    public abstract void buildPartC();

    public Product getResult() {
        return product;
    }
}

// ConcreteBuilder类，实现了Builder接口，构建具体的Product对象
class ConcreteBuilder extends Builder {
    public void buildPartA() {
        product.setPartA("PartA");
    }

    public void buildPartB() {
        product.setPartB("PartB");
    }

    public void buildPartC() {
        product.setPartC("PartC");
    }
}

// Director类，使用Builder接口来构建Product对象
class Director {
    private Builder builder;

    public Director(Builder builder) {
        this.builder = builder;
    }

    public void construct() {
        builder.buildPartA();
        builder.buildPartB();
        builder.buildPartC();
    }
}

// 测试程序
public class BuilderDemo {
    public static void main(String[] args) {
        Builder builder = new ConcreteBuilder();
        Director director = new Director(builder);
        director.construct();
        Product product = builder.getResult();
        System.out.println(product.getPartA() + " " + product.getPartB() + " " + product.getPartC());
    }
}

这个示例中，Product类表示需要被构建的复杂对象，Builder类定义了如何构建Product对象的接口，ConcreteBuilder类实现了Builder接口，构建具体的Product对象，Director类使用Builder接口来构建Product对象。在测试程序中，首先创建了一个ConcreteBuilder对象和一个Director对象，然后通过Director对象来构建Product对象，最后获取构建完成的Product对象并输出。